"Paint is paint." That's what I told myself as Dave Rempis was propelling big swaths of sound out of his baritone sax at the Lily Pad a week ago Wednesday. The Chicago-based Rempis — who usually shows up in these parts in the Ken Vandermark 5 — was in the midst of a two-week tour with drummer Frank Rosaly in support of their new Cyrillic (482 Music). The CD is divided into seven discrete tunes, the longest 16 minutes, but at the Lily their first "tune" was 40 minutes without a break. They kicked off with Rempis on alto, an upward melodic gesture of long tones against a fast free pulse from Rosaly — dry, snares off, and only spare cymbal splashes here and there. Rempis whipped up thicker, long clusters of notes riding atop Rosaly and then broke down into shorter fragmentary phrases, and Rosaly thinned out into clatters along his rims and cymbal edges. Rempis dropped out and Rosaly clattered along — not too loud, still nice and dry. Then Rempis broke out his bari and established a five-note rhythmic motive, moving it around on the big horn, from a deep middle register and then up toward altissimo with broad clotted gestures.

That's when I had my epiphany — in the words of Jeffrey Tambor as the critic Clement Greenberg in Ed Harris's film Pollock. There is no representation — just paint. Or, in this case, just sound. Rempis and Rosaly didn't play a steady meter all night, and they only flirted with chord changes and song forms. (With not even a bass, it was hard to get a fix on harmonies.) But the music swung hard. They built those broad gestures from rhythmic motives, and at their best, they could get you nodding along, get your body moving, as surely as Count Basie could get you to tap your foot or Metallica can get you to nod. Textures thickened and then thinned — though Rosaly mostly stuck to the dry, snare-less drum sound. Rempis moved from alto to baritone to tenor and back again, filling the small room with ferociously controlled articulation, timbre, and pitch. This was free music, but also deliberate, disciplined. And like the action painters Greenberg wrote about, Rosaly and Rempis were acutely aware of the relationship of mark to ground, sound to silence.

For another 40-minute set, Boston pianist Pandelis Karayorgis joined the duo. At times, the free-running single-note patterns in his left hand acted as a bass. But he avoided chording too many harmonies, content to run lines in tandem with Rempis, playing call-and-response in short phrases, or dripping his own brightly colored skeins on the canvas.